1. Field of the Invention
The present invention relates to recreational vehicles and, in particular, relates to motor homes and travel trailers that are adapted to expand in size so as to increase the effective interior living space of the vehicle.
2. Description of the Related Art
Recreational vehicles (RVs) have become an increasingly popular and common means of recreation. RVs are vehicles that include a living space inside and can be either self-propelled as in a motorhome or can depend on another vehicle for their motive power as in campers or trailers.
A typical RV comprises a chassis and a frame upon which coach bodywork is mounted. The coach bodywork, which provides and encloses the living space of the RV, typically comprises a floor and vertical walls that extend upwards from the floor. A roof usually rests on and depends on the vertical walls of the body for structural support.
Inside the coach body, RVs typically provide sleeping areas, cooking facilities, and self-contained water supplies and toilet facilities. More elaborate RVs can include refrigerator/freezer units, showers and/or bathtubs, air conditioning, heaters, built in generators and/or power inverters, televisions, VCRs, and clothes washer and dryers. RVs provide many of the amenities of a residential home while on the road away from home and are popular for this reason.
RV users will typically use the RV to travel to a recreational area and live in the RV for some period of time. RV users often have families with children and, as their trips are often of a recreational nature, will often invite friends or family along on the trip. Some people even use a RV as their primary residence.
It can be understood that since a RV will often be used by a large number of people and often for an extended period of time, the RV manufacturers and customers will seek to maximize the amount of usable living space inside their RVs. However, vehicle codes restrict the maximum width and length of vehicles that may be driven on public roads. Also, as a vehicle increases in size, it might become difficult to drive or even become too large to fit into desired destinations. In addition, as the RV gets physically larger, more fuel is required to move it, which increases the cost of operation.
One feature that RV manufacturers have used to increase available living space in RVs without increasing the overall vehicle size is the incorporation of slide outs. Slide outs are movable sections of the RV that can extend outward from the RV coach body and effectively increase the interior floor space. Slide outs typically have rigid walls on three sides as well as a rigid roof and floor. The fourth wall space is open to the interior of the RV to provide access between the interiors of the slide out and the RV.
Slide outs typically have two normal positions of use: the live-in and the travel position. When the RV reaches its destination and comes to rest, the slide out can be extended to its live-in position. By extending the slide out to the live-in position, the footprint of the RV is increased along with the available interior floor space. When the user wants to move the RV, the slide out is retracted to the travel position. In the travel position, the outer wall of the slide out typically lies flush with the outer walls of the RV coach and the slide out is secured in some manner to allow the RV to travel.
Designers of the RV preferably take into account the loading that the RV will undergo when designing the slide out. For example, the RV body will likely undergo static loading due to the weight of the passengers and cargo, and the RV body will likely undergo dynamic loading due to forces induced by the various driving surfaces over which the RV drives.
As stated, an opening must be provided in the wall of the RV body to accommodate the slide out. As a result, structural support is lost from the RV body at the opening and the stiffness and strength of the RV body is degraded. It will be understood that as the slide out gets larger and the size of the opening in the side of the RV increases, the stiffness and strength of the RV body become further degraded.
More specifically, as the recreational vehicle is travelling down the road, vibrations and other mechanical forces are transmitted to the walls via the wheels. At the opening for the slide out, portions of the wall are not connected to each other which results in these portions having a greater tendency to move with respect to each other. For example, the bottom of the RV wall below the opening is likely to flex with respect to the top of the RV wall above the opening because structurally supportive material has been removed to make the opening. Similarly, the RV wall on one side of the opening is likely to flex with respect to the RV wall on the other side of the opening because structurally supportive material has been removed to make the opening. Over time, these movements may result in damage to the walls of the recreational vehicle. For example, there are often cabinets, surface treatments and fixtures mounted on interior surfaces of the walls. If these items are mounted on the interior surface immediately adjacent the slide out opening, these items may ultimately work loose from the wall presenting a less pleasing appearance.
Moreover, excessive flexing of the walls of the recreational vehicle with respect to the slide out opening can cause the walls of the RV to come into contact with the walls of the slide out. This may result in deformation of the interface between the walls and the slide out member. This deformation may further result in the slide out no longer sealing with respect to the main housing of the recreational vehicle or can further inhibit unimpeded motion of the slide out between the deployed and retracted configuration.
On a related note, the unsupported sections of the RV walls may vibrate against the walls of the slide out and thereby create audible noise. Disadvantageously, this vibratory noise may create an annoyance for the RV users when travelling.
These problems have resulted in recreational vehicle manufacturers limiting the size of the slide out openings in the side walls of the recreational vehicle. As such, the slide outs themselves are also being limited both in terms of their height and their length. It will be appreciated that slide outs generally have a lower ceiling height than the main housing of the recreational vehicle due to the floor and ceiling of the slide out being inset from the floor and ceiling of the main housing. The loss of structural reinforcement as a result of the slide out opening further induces recreational vehicle manufacturers to further reduce the height of the opening so as to reduce the loss of structural reinforcement. This further reduces the height of the slide out area, thereby limiting its use and comfort when in the deployed configuration.
Moreover, the length of the slide out opening is also often limited to limit the loss of structural support along the side wall of the recreational vehicle. This reduces the overall floor area of the slide out and thus the overall available living space of the recreational vehicle when the slide out is in the deployed configuration.
From the foregoing, it is apparent that there is a need for a recreational vehicle having a slide out that allows for greater dimensioned slide outs. To this end, there is a need for a slide out assembly that can be expanded both in length and in height without a significant loss of structural support in the main housing so that the potential for damage or loss of integrity of the recreational vehicle housing when the slide out is in the retracted position during travel is reduced.